Basket Case Yamaha XS 250

[gbjeppm]

If the points are, as I think, on the camshaft? Then swap the coil trigger wires over so that the "wrong" coil is connected and try that.

I am sure that it is ok, and its firing correctly.

But i did swap the trigger wires over and it made no difference.

I also know that i am getting a signal from the points up the trigger wire.

[K2-K6]

Strange that you get not even a pop from it.

If the plugs are wet enough though it probably wouldn't make a difference with starter fluid either.

Can you drain the carb float bowls and leave them empty,  then crank it with throttle open so that it can draw no fuel at all,  then give it a mist of starter fluid to judge if you get any response.

[gbjeppm]

Can you drain the carb float bowls and leave them empty,  then crank it with throttle open so that it can draw no fuel at all,  then give it a mist of starter fluid to judge if you get any response.

Yes i can, will do that tomorrow probably.

I did just manage to get a couple of backfires in the carb and a loud bang through the exhaust when i opened the thottle whilst cranking.

That is a major step forward at least. So back to looking at timing and fuel delivery i guess, but progress of sorts.

[Bryanj]

Might sound daft but with that check that spark is on correct cylinder

[gbjeppm]

Might sound daft but with that check that spark is on correct cylinder

Yes i am sure i have done something stupid, i just need to find it 

[kevski]

Compression sounds OK for a cold motor, should test them when fully warmed up, maybe condensers, do a direct live to the coils to eliminate the rest of the electrics.

[gbjeppm]

Compression sounds OK for a cold motor, should test them when fully warmed up, maybe condensers, do a direct live to the coils to eliminate the rest of the electrics.

Thanks Kev, new condenser, and direct live to the coils is in place.

I have though bitten the bullet and ordered new points, its the only part of the ignition system that i have not changed, and I want to discount them, They are very worn.

[kevski]

Don't leave the direct live permanently connected it will stuff the coils up.

[gbjeppm]

Don't leave the direct live permanently connected it will stuff the coils up.

Thanks Kev for the reminder, all is good.

[gbjeppm]

Well finally i got her running properly.

It turns out that the cam was two teeth out. I decided to pull the cam cover again as i was still feeling that timing/ignition was not correct.

When i took the cam cover off the first time  to clean up the valves,I marked the chain and sprocket and put it back on in the same place and did not check it. On closer inspection it was wrong when i got the bike, whoever put it back together before me, has lined up everything at 12 o clock, perpendicular to the ground, not perpendicular to the head, which was two teeth out.

Put it back together and fired up no worries for the first time in 10+ years.

That also explains the lowish compression, now it is 125.

Thanks all for your thoughts and comments.

[Rozabikes Tim]

Result. Bet that was a good feeling!!

[Bryanj]

Nice one, dont expect it to be fast though

[gbjeppm]

Result. Bet that was a good feeling!!

Yes, i was really starting to doubt myself....

And of course it was my own fault 

[gbjeppm]

Nice one, dont expect it to be fast though

i have heard that it can do 70 downhill with a following wind.... not sure i want to do more than 40 on it

Anyway it will be a while, as i am going to take it down to the frame and paint it now that i know it runs, and give it a slight modernisation, headlight, indicators, exhaust, seat etc. All need to be changed anyway, and stock parts are silly money.

[Rob62]

Quite a rare classic these days, popular enough back in the day but you never see them out and about these days. I see lots of jap classics at squires cafe, its a popular venue for classic bike enthusiasts but I don’t remember seeing any XS250’s... should be a bit of a celebrity when you finally get out on her.. good luck and more photo’s please.